Natural gas is a major energy source. Its importance has increased in the past decades, and it is expected that its significance will grow further in next decades. A main concern in the natural gas production is the presence of acidic contaminants. Many natural gas fields are known that contain a few percents of acidic contaminants, and many gas fields are known to comprise large amounts of acidic contaminants, up till 50 vol % or even more. In general, the presence of several volume percents of carbon dioxide and/or hydrogen sulphide is acceptable, as conventional technologies are known to remove such amounts of acidic contaminants from the hydrocarbon fraction. Suitable conventional techniques are the absorption of acidic contaminants with aqueous amine solutions or with cold methanol, including the regeneration of the absorption liquids. The removal of higher amounts of acidic contaminants from natural gas, e.g. 10 vol percents or more, would result in very large removal units, including many stages, requiring very high investment and operational costs.
Thus, there is a need for new techniques for the easy and quick removal of acidic contaminants from natural gas streams containing high mounts of these compounds. In the past, the use of membranes has been considered for the removal of the acidic contaminants. However, up till now no process has be developed for the quick and easy removal of acidic contaminants from natural gas streams containing high mounts of these compounds.